<!doctype html>
<meta charset="utf-8">
<title>CSS Pseudo-Elements Test: highlight cascade: inheritance of custom properties</title>
<link rel="author" title="Stephen Chenney" href="mailto:schenney@chromium.org">
<link rel="help" href="https://drafts.csswg.org/css-pseudo-4/#highlight-cascade">
<link rel="help" href="https://github.com/w3c/csswg-drafts/issues/6641">
<meta name="assert" content="This test verifies that custom properties used in highlight pseudos are taken from the originating element.">
<script src="../support/selections.js"></script>
<link rel="stylesheet" href="../support/highlights.css">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
  :root {
    --background-color: green;
    --decoration-color: green;
  }
  ::selection {
    --decoration-color: purple;
  }
  div::selection {
    --background-color: blue;
    background-color: var(--background-color, red);
  }
</style>
<body>
  <div>Some text</div>
</body>
<script>
    selectNodeContents(document.querySelector("body"));

    const body_selection = getComputedStyle(document.querySelector("body"), "::selection");
    const div_selection = getComputedStyle(document.querySelector("div"), "::selection");
    test(() => void assert_equals(body_selection.getPropertyValue("--background-color"), "green"),
        "body ::selection uses the originating custom property");
    test(() => void assert_equals(body_selection.getPropertyValue("--decoration-color"), "green"),
        "body ::selection does not use its own custom property");
    test(() => void assert_equals(div_selection.getPropertyValue("--decoration-color"), "green"),
        "div::selection uses the originating element custom property");
    test(() => void assert_equals(div_selection.getPropertyValue("--background-color"), "green"),
        "div::selection does not use its own custom property");
</script>
